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Because every DIY I've seen are for manual cars without the stupid fan in the way. This DIY is for the rest of us who own automatic cars. Also for everyone that is in need of possible pulling out their water pump since removing the fan clutch nut is the exactly what you will have to do on all cars (whether manual or automatic) to get the water pump out.

The belts DIY is easy in itself. The large pictures and crayola text within each picture below should give anyone with a brain the basic idea of what to do. I've changed belts on older BMW cars before without having to bother with the fan (like on the M44 engine) so the fan removal part of the M54 DIY was always a mystery to me and many with automatic E46 cars. Many of us followed all those website and forum DIYs, that was using manual cars for their DIY projects, up until we realized there was a big a$$ fan in there for our cars and couldn't go any further.

This DIY shows you how to safely remove the fan, belts, look at the inevitable water pump/thermostat failure regions and put everything back in.

My DIYs do not end in the middle, like most DIYs, and leave you stranded . I show you how to double check what you did and safely put everything back in there.

WATER PUMP and THERMOSTAT DIY QUICK INFO:
Only read this bit if you are interested in these tasks.
Said and done, if you can do this DIY then the water pump/thermostat DIYs will be not much more difficult, if not as easy. With the fan clutch out and shroud out and coolant drained, all that is left is removal of the bolts and bits that hold the water pump and thermostat in place. These are right there in front of you.

My car only has 49k on the clock, as of this writing, but it is still a 7-8 year old car so I plan of changing my plastic OEM pump and thermostat housing for the metal high performance water pump and an aluminum body thermostat housing over the next couple of months just to be safe.

After you are done and double checked everything (including those front-fan shroud/radiator connector plugs) get yourself cleaned up and go start your car leaving the hood up and the windows down. Keep your hand on the key in case you have to shut off the engine immediately.

If the engine starts up okay and everything sounds and feel normal (no squealing or fierce vibrations) after a minute or two go look under the hood. The fan and belts should be moving okay. My fan seemed wobbly for the first couple of minutes but after it was okay-leaving me thinking it was just my imagination.

The worse that can happen is usually the fan blades either break off spontaneously and/or the fan comes off, thus exploding sending pieces of hard plastic everywhere. This is why you NEVER drop the fan, lay it flat or damage it if during the DIY you plan on using it again. Even if one blade gets chipped or scuffed then the fan can quickly lose equilibrium and wobble itself to bits destroying your engine block and hood.

This is also why it is best to first start the engine with the hood up and everyone clear of the engine bay, and your hand on the key in case you have to cut the engine off pronto. I think the rule of thumb is if your fan doesnít explode right away you should be good.

That is it! DIY completed! Now itís time to think about that inevitable WATER PUMP failure prevention upgrade and Thermostat Housing upgrade DIY.
Enjoy,
Delmarco.

Man this was very helpful. Thanks. I did not have the luxury of ordering the removal tools and waiting because I needed my car but, I went to Autozone and they have a free loaner tool program. They loaned me an universal removal tool and it worked like a charm.

9. REMOVE LOWER MECHANICAL TENSIONER:
- Tools: 13mm and 16mm socket, 3-inch socket extension
- Spare allen wrench of just under about 5mm diameter (mine was unmarked)
- From underneath, turn the 16mm molded nut clockwise till the tabs line up - Slip the spare 5mm allen wrench into the two tabs to lock them in place
- With a 13mm box wrench on a 3-inch extension, remove both bolts
- Remove lower mechanical air conditioning tensioner
- Leave the spare allen wrench in place (how do you safely remove it?)
- Mark the tensioner as the AC tensioner (they are slightly different)
Note: AC mechanical tensioners were redesigned in 8/2002 so compare with new

The SIZE of the tensioner temporary hold-fast pin:
- A 5mm allen wrench fits; 6mm does not fit
- A 3/16ths allen wrench fits; 7/32ths does not
Note: The L-shaped steel pin from the factory tensioner is 11/64ths round.

This was an excellent. I just did my belt replacement in approximately an hour following this instruction exactly. The only thing I couldn't do was figure out where to put the 5/8 socket to release the main pulley. So I ended using the torx wrench. It worked fine for me. Thanks again.

Although this is an old thread, but it really provides good information. I want to warn people not to use a regular 32mm wrench to remove the fan clutch. Although it may seem to work just fine, but you can easily damage the fan clutch and not knowing it until the fan starts to wobble. I know it because I made the mistake.

Several months after I replaced my tension pulleys, I started to experience vibration at idle speed. I replaced the engine mount and tried various other methods to address the vibration issue. Eventually, out of dumb luck, I realized my fan was wobbling.

Installing the new fan clutch, I realized how tight it was with my regular 32 mm wrench to fasten the new clutch. It then struck me that I must have damaged the original fan clutch with my previous DIY job.

Just want to share this piece of advice to invest the money and get the special tool. It will save time and money.

Here is a picture of my damaged fan clutch after it was damaged 10 months ago. Notice how much the nut is off center.